First of all, please forgive me for my very bad English, (I’m French).
I use FMod with Delphi (in remplacement of XAudio).

I have a problem.
I’m making a soft which crosfade two MP3 files. To do this, I load the two MP3s, i play the first, and then the second.
It works all right. But, after 10 or more song played, there is no more sound output.
I think it’s a problem of full channels.

You close flux2 before loading it ??
i would do a crossfade this way : load the two songs, when the first song reached the end, in a loop, i would reduce progressivly it’s volume to zero and increase the volume of the second one.